At the beginning of a bobsled race, teammates push their bobsled along the track before jumping into it.

a. before the teammates jump in, they push the bobsled (m = 150 kg) from rest to a speed of 4.2 m/s. how much kinetic energy does the bobsled gain?

b. how much work did the bobsled team do? explain how you found the answer.

c. if the teammates pushed the bobsled with a force of 500 n, over what distance did they apply the force?

d. later, the bobsled is racing down the track at a speed of 28 m/s. with the team in it, the bobsled has a total mass of 430 kg. how much work must be done by air resistance to slow down the bobsled to 25 m/s?

a) KE=1/2 mv^2=1/2*150*4.2^2=1323 J

b) Work-energy theorem states that work equals the gained KE, so W=KE=1323 J

c) d=W/F=1323/500=2.65 m

d) Again apply work-energy theorem:

W=1/2*m(v2^2-v1^2)=1/2*430*(25^2-28^2)=--34.185 J

this is an example of "committed" time.

committed time, as contracted time, takes need over essential and available time since it is seen as profitable work. it alludes to the time allotted to keep up a home and family. at the point when a man is commuting using committed time this individual may feel that the drive is an obligation to family, for example, strolling youngsters to class or driving a mate to work. contracted and committed time clients may feel that their commute could really compare to the commute of important or leisure time clients on the grounds that their commute is profitable work. in this manner, they might be more disposed to pick a mechanized method of movement.  

conduct current i mean it makes sense